ES2998583T3 - Reformer furnace and its use for steam reforming - Google Patents

Abstract

The invention relates to a reforming furnace for the catalytic reforming of a carbon-containing feedstock with steam. The reforming furnace has a steel structure serving as a framework for a fireproof lining and for securing burners, reforming tubes, and feed and discharge ducts. The burners and reforming tubes are arranged in rows, parallel to each other and alternating. The steel structure comprises several main support units, each main support unit having at least two vertically running supports and one horizontally running main support connecting the supports. According to the invention, the main supports of the main support units are arranged parallel to the rows of burners and the rows of reforming tubes. This type of steel structure allows the reforming tubes and burners to be evenly spaced along the entire length of the reforming furnace. This results in advantages regarding the maximum operating temperature of the reforming tubes, which extends their service life. (Automatic translation with Google Translate, no legal value)

Description

DESCRIPTION

Reformer furnace and its use for steam reforming

Technical field of the invention

The invention relates to a reformer furnace for the catalytic reforming of a carbon-containing feedstock with water vapor, the reformer furnace comprising a radiation space defined by a plurality of walls, delimited from the external environment, and the radiation space having a steel construction made as a skeleton for fixing supply and discharge pipes, burners and reformer furnaces arranged vertically.

State of the Art

Reformer furnaces for the catalytic reforming of carbon-containing feedstocks with steam are known in a variety of embodiments. A known example of a reformer furnace for the catalytic reforming of carbon-containing feedstocks is the steam reformer for reforming natural gas and steam to produce synthesis gas, a mixture of carbon monoxide and hydrogen, as well as typically undesired by-products such as carbon monoxide. Such reforming processes proceed endothermically and slowly, so that for the reaction of the carbon-containing feedstock with steam, an external combustion source is required to heat the catalyst-filled reformer tubes (also reaction tubes) of the reformer furnace.

In industrial-scale installations, a construction method has become established that uses an essentially box-shaped furnace with vertically arranged reformer tubes. The interior space of the entire reformer tube system forms the reaction space of the reformer furnace. In this case, the reformer tubes are arranged in one or more side-by-side rows.

Each row of reformer tubes is typically heated by two rows of burners, where one row of reformer tubes is arranged centrally between two rows of burners running parallel to the rows of reformer tubes to ensure uniform heating of the reformer tubes. In this case, there is no distinction between wall-mounted and non-wall-mounted burner rows. In the case of wall-mounted burner rows, the burners are arranged between a reformer furnace wall and a row of reformer tubes. In the case of a non-wall-mounted burner row, the burners are arranged between two rows of reformer tubes.

The burners are arranged within the so-called heating space of the reformer furnace. The feed gas supply and product gas discharge to and from the reformer tubes necessarily take place outside the heating space, so the walls of the reformer tubes define the spatial separation between the reaction space and the heating space.

The entire heating space and reformer tubes are also called the radiation zone of the reformer furnace.

The burners in the burner rows are supplied with air and fuel gas via supply ducts and, in the most common construction forms, are arranged on the roof or bottom of the reformer furnace, where the burner flames are correspondingly directed perpendicularly downwards toward the bottom of the reformer furnace or perpendicularly upwards toward the reformer furnace roof. Other burner arrangements are also known, such as on the side walls of the reformer furnace for lateral heating, or a terraced arrangement for diagonal heating, but are less commonly used.

The radiation chamber of a reformer furnace with one or more rows of reformer tubes and several rows of burners is generally constructed of steel, which serves as a skeleton for the refractory lining of the heating chamber. In addition, the supply and discharge piping systems, the burners, and the reformer tubes are fixed to and supported by this steel structure.

The roof of the radiant space is primarily constructed as a self-supporting or suspended steel structure, since vertically arranged supports (e.g., pillars) for load transfer cannot be guided through the heating space. Therefore, the main support units, consisting of vertical supports and horizontal main supports, are arranged so that the supports extend along the wall and outside the heating space.

The lateral length of the reformer furnace is defined by the length of the reformer tube rows and the burner rows, i.e., by the number of reformer tubes and burners per reformer tube row or burner row. If the lateral length of the reformer furnace exceeds a certain dimension (for example, 6 to 7 meters), static limitations require more than two main support units arranged on the front sides of the reformer furnace to transfer the loads caused by the longer burner rows and reformer tube rows. Therefore, in this case, a third main support unit or, if necessary, further main support units must be arranged between two main support units arranged on the front side. The distance from main support unit to main support unit is essentially the same in this case, and the burner rows and reformer tube rows run orthogonally to the main supports of a main support unit, which run horizontally to the roof of the radiation space.

This steel construction structure has established itself in state-of-the-art reforming furnaces, as it is the most economical type of steel construction configuration.

However, the aforementioned arrangement of main support units also entails disadvantages. By means of additional main support units not arranged on the front sides of the reformer furnace, i.e., by increasing the number of main support units to three or more in large reformer furnaces, the main supports of the main support units running horizontally to the roof are not mounted on the wall, but rather centrally across the radiation space of the reformer furnace. By means of a centrally running main support, a greater distance from the reformer tube axis is required at this point. In other words, the distance from one reformer tube to the next reformer tube in a row of reformer tubes must be increased at the point where the main support of the main support unit runs along the roof of the radiation space.

For example, the reformer tube centerline in a standard reformer furnace is approximately 300 mm from reformer tube to reformer tube. In the area of a centrally running main support, this reformer tube centerline distance can also increase to more than 500 mm.

This design limitation results in higher operating temperatures for the reformer tubes in the area of the main support shafts. This generally leads to a reduced service life of the reformer tube and, consequently, higher safety requirements in the reformer furnace design. The higher temperature in these reformer tubes is due to the higher visibility factor of the burner flames than in other reformer tubes located within a row of reformer tubes, where the distances from the reformer tube axis are shorter.

In this case, the formation of so-called bays within the reformer furnace is also frequently mentioned. Accordingly, all distances from the reformer tube axis are equal (small) within a bay and larger between adjacent reformer tubes of two adjacent bays. Examples of reformer furnaces with such bays are disclosed in EP 3182 003 A and EP 3279561 A1.

Document US 2019/0321800 A1 discloses a box-shaped reformer furnace that can be subdivided into several sections. The upper ends of the reformer tubes are flexibly mounted on a support structure located above the reformer, which comprises support arms. The support arms are connected in two adjacent rows to each reactor tube. Each of the support arms is supported by a horizontal beam via a spring arrangement.

Description of the invention

The task of the present invention is to at least partially overcome the aforementioned disadvantages of the state of the art.

An object of the present invention is in particular to provide a reformer furnace in which the distances between two adjacent reformer tubes within a row of reformer tubes are equal in the entire reformer furnace.

Another object of the present invention is to provide a reforming furnace which does not comprise bays.

Another object of the present invention is to provide a reformer furnace in which the reformer tubes have more uniform operating temperatures than is the case with known reformer furnaces.

The independent claims contribute to at least partially fulfilling at least one of the above objectives. The dependent claims provide preferred embodiments that contribute to at least partially fulfilling at least one of the objectives. Preferred configurations of components of one category according to the invention are, where appropriate, also preferred for components of the same name or corresponding components of a different category according to the invention.

The expressions "that presents", "that comprises" or "that includes", etc., do not exclude the possibility that other elements, constituent substances, etc. may be included. The indefinite article "un" does not exclude the possibility that a plurality may be present.

The objects of the present invention are solved at least in part by a reformer furnace for the catalytic reforming of a carbon-containing feedstock with steam, which has a radiation space defined by a plurality of walls, delimited from the outside environment, wherein the radiation space includes a steel construction made as a skeleton for fixing supply and discharge pipes, burners and reformer tubes arranged vertically, wherein the burners are arranged for the generation of downwardly or upwardly oriented flames for heating the reformer tubes, and wherein the burners and reformer tubes are arranged within the radiation space in rows as rows of burners and rows of reformer tubes, wherein the burner rows and the rows of reformer tubes are arranged alternately and parallel to each other, and

The steel construction has a plurality of main support units, each main support unit having two supports arranged on the wall that run vertically, as well as a main support connected through the supports and running horizontally, which extends over the entire length of the radiation space, and where

The main supports are configured for fixing supply and discharge pipes, burners and reformer tubes, and

The steel construction has a plurality of horizontally extending transverse supports, which connect the supports of the main support units to one another. According to the invention, it is provided that the main supports of the main support units are arranged parallel to the reformer tube rows and burner rows and

that the cross supports are arranged orthogonally to the rows of reformer tubes and rows of burners at least in part.

According to the invention, the horizontally extending main supports of the main support units, in particular those extending in the roof of the radiation space, are arranged parallel to the reformer tube rows and the burner rows. In this way, the reformer tubes can be arranged continuously over the entire length of the radiation space at the same spacing, since it is not necessary to widen the distances from the reformer tube axis by means of main supports extending orthogonally to the reformer tube rows.

The main supports of the main support units carry the main load of the supply and discharge pipes, which are attached to the main supports of the steel structure. The supports of the main support units, arranged vertically, are preferably attached to the ends of the main supports.

The cross supports connecting the supports of the vertically extending main support units are arranged orthogonally, at least in part, but also parallel to the reformer tube rows and the burner rows. The cross supports serve to stabilize the steel structure and do not carry the main load of supply and discharge pipes, burners, and reformer tubes. In one example, the cross supports are arranged at the bottom of the radiation space. Since the cross supports have a substantially smaller thickness than the main supports of the main support units, they can also be arranged in the space between the burner axes and the reformer tube axes without requiring an increase in the distance between two individual reformer tubes. In principle, the cross supports can be attached at any point between the lower and upper ends of a support of a vertically extending main support unit, or at one of the ends.

In reformer furnaces known from the state of the art, only the cross supports run parallel to the reformer tube rows and the burners. Since the cross supports are not used to carry the main load of the supply and discharge pipes, burners, and reformer tubes, corresponding static limitations arise, and therefore an orthogonal arrangement of the horizontally running main supports is necessary. This leads to the following disadvantages.

The horizontal main supports of the main support units, arranged at least vertically, preferably run along the roof of the radiation space. In this case, the main supports extend along the entire length of the radiation space. In this case, "total length" means that the length of the main supports is designed to correspond to the size requirement of the radiation space, so as to enable the most uniform heating possible of the reforming tubes. In this case, the length of the radiation space is defined by the distance between the two end faces of the radiation space, i.e., the distance between the front and rear sides.

The parallel arrangement of the main supports with respect to the burner rows and the reformer tube rows produces the following advantages:

• The service life of all reformer tubes is increased, as load peaks do not occur in certain reformer tubes.

• The maximum temperature measured in a reformer tube (T<max>), relative to the entire reformer tube, is lower. This allows the wall thickness of the reformer tubes to be reduced, leading to material savings and thus cost savings.

• A reduced wall thickness leads to lower thermally caused operating stresses in the reformer tubes, which in turn extends the service life of the reformer tubes.

• A reduced wall thickness also leads to improved heat convection from the radiation space into the reformer tube. This increases the temperature in the catalyst bed (cleavage gas temperature), which allows for more efficient systems (increased reformer efficiency).

Depending on the system size, the expected reduction in T<max> in this case ranges from approximately 5 to 10 Kelvin. In this case, it is known from experience and many years of research that 10 Kelvin less (relative to T<max>) corresponds to a possible reduction in wall thickness of 10 percent. If the wall thickness is to be maintained, this would require an increase in the theoretical service life of a reformer tube of 20,000 to 40,000 hours.

The reformer tube rows and burner rows are arranged alternately and parallel to each other. Since each reformer row must be heated from two sides by two burner rows, a wall-mounted burner row is preferably arranged first along the lateral length of the radiation space. Alternating, and depending on the size of the reformer furnace, a certain number of reformer tube rows and non-wall-mounted burner rows follow, with the last of the burner rows, on the side opposite the "first" wall-mounted burner row, itself a wall-mounted burner row. This preferably results in the following arrangement: In this case, n = 0 or a natural number with n > 1.

The burners at the ends of a burner row and the reformer tubes at the ends of a reformer tube row are arranged on the front sides (front and rear sides) of the radiation space.

A preferred embodiment of the reformer furnace according to the invention is characterized in that the number of main support units is a function of the number of reformer tube rows and/or a function of the number of burner rows. The number of main support units preferably increases with the number of reformer tube rows and burner rows, since the simplest embodiment in terms of construction is when, with an increasing number of burner rows and reformer tube rows, a correspondingly larger number of main supports are provided for securing the burners and reformer tubes.

A preferred embodiment of the reformer furnace according to the invention is characterized in that the radiation space has a number h of main support units and has a number r of reformer tube rows, where between h and r the relationship h = r 1 is taken into account. The number of main support units preferably results from the number of reformer tube rows present, where the radiation space preferably contains one more main support unit than the rows of reformer tubes arranged in the radiation space.

A preferred embodiment of the reformer furnace according to the invention is characterized in that the radiation space has a number h of main support units and a number b of burner rows, where the ratio h = b is taken into account between h and b. The number of main support units preferably results from the number of burner rows present, where the radiation space preferably contains the same number of main support units as the reformer burner rows arranged in the radiation space.

More preferably, for the reformer furnace h = r 1 and h = b are considered.

A preferred embodiment of the reformer furnace according to the invention is characterized in that the number of main support units is not a function of the length of a reformer tube row and/or the number of main support units is not a function of the length of a burner row. Since the main supports and the main support units are arranged parallel to and along the reformer tube rows and the burner rows, the number of main support units is not determined by the length of the burner rows and the reformer tube rows, as is known from the prior art in the case of orthogonal arrangement. Rather, the burner rows and the reformer tube rows can in principle be designed to be of any length within the radiation space, whereby the number of main support units is determined solely by the number of burner rows and reformer tube rows.

A preferred embodiment of the reforming furnace according to the invention is characterized in that between two adjacent main support units

• a row of burners is arranged or

• a row of burners and a row of reformer tubes are arranged adjacent to the burner row. Between two adjacent main support units, there is preferably a row of burners or a row of burners and a row of reformer tubes adjacent to the burner row, as this is simple and therefore preferable in terms of construction.

In this case, a single burner row, a wall-mounted burner row, is preferable, as it is easily feasible in terms of construction.

A preferred embodiment of the reformer furnace according to the invention is characterized in that two of the plurality of main support units are arranged on two opposite walls of the radiation space, respectively mounted on the wall, the main supports of the main support units positioned on the wall extending parallel to the respective wall. A plurality of main support units comprises at least two main support units in the case of the smallest possible embodiment of the reformer furnace, for example in the case of using only a single row of reformer tubes and two rows of burners, whose burners heat the reformer tubes of the single reformer tube row from two sides. In this case, both main support units are arranged on the wall respectively, the main supports extending along the side walls from one end side to the opposite end side of the radiation space. In the case of larger reformer furnaces comprising more than a single row of reformer tubes, additional main support units are usually required. These additional main support units are arranged between the main support units arranged on the wall, where their main supports run horizontally and away from the side walls, as well as along the roof of the radiation space.

A preferred embodiment of the reformer furnace according to claim 1 is characterized in that the main support units arranged on the wall have more than two vertically extending supports arranged on the wall. The main support units arranged on the wall can have more than two vertically extending supports, for example a third support, which are arranged centrally between the two end supports of the main support units. In this way, the support strength of the main support units arranged on the wall can be reinforced/improved. Since no reformer tube row or burner row runs immediately along the wall of the radiation space, an additional vertical support arranged at this point does not interfere.

A preferred embodiment of the reformer furnace according to the invention is characterized in that all distances between two adjacent reformer tubes within a row of reformer tubes and/or all distances between two adjacent burners within a row of burners within the total radiation space of the reformer furnace are equal. This regularity and symmetry in the arrangement of burners and reformer tubes is made possible for the first time by the arrangement of main support units according to the invention and is preferred, since this leads to uniform heating of the reformer tubes. Temperature peaks on the walls of the reformer tubes and in the interior space (catalyst bed) of the reformer tubes are thereby avoided as best as possible. This also leads to uniform flame patterns of the burners, avoiding, as far as possible, for example, undesirable curvature of the flames toward the center of the reformer furnace.

A preferred embodiment of the reformer furnace according to the invention is characterized in that all distances between two adjacent reformer tubes, measured by horizontals running measured through the adjacent reformer tubes between two reformer tube axes are less than or equal to 500 mm, preferably lie in a range of 250 to 450 mm, more preferably lie in a range of 280 to 320 mm.

A preferred embodiment of the reforming furnace according to the invention is characterized in that the temperature of the product gas withdrawn through the discharge lines into the medium amounts to up to 950 °C, preferably in a range of 900 to 950 °C, more preferably in a range of 925 to 950 °C.

A preferred embodiment of the reformer furnace according to the invention is characterized in that the steel structure serves as a skeleton for a refractory lining of the radiation space, the space within the refractory lining defining a heating space for heating the reformer tubes. The steel structure is arranged within the so-called radiation space. The walls or outer walls of the radiation space delimit it from the surrounding environment. The steel structure, in turn, represents the skeleton for a refractory lining of the reformer furnace, this lining being arranged toward the interior of the radiation space as seen from the outer walls.

A preferred embodiment of the reformer furnace according to the invention is characterized in that each main support unit has a frame structure arranged above the main support unit and force-coupled to the main support. The frame structure is force-coupled to the main supports by means of screw connections. Such a frame structure allows additional loads to be transferred across the main supports of the main support units.

The tasks are further solved at least in part by using the reformer furnace according to the invention according to at least one of the aforementioned embodiments for steam reforming a carbon-containing feedstock, especially natural gas. The carbon-containing feedstock can be any carbon-containing feedstock known to those skilled in the art and accessible for steam reforming to generate synthesis gas.

Examples

The invention is explained in more detail below by means of an exemplary embodiment. In the following detailed description of the exemplary embodiment, reference is made to the accompanying drawings, which form an integral part thereof and in which specific embodiments of the invention are illustratively represented. In this context, directional-specific terminology such as "up," "down," "front," "behind," etc. is used in relation to the orientation of the figure(s) described. Since components of embodiments can be positioned in a variety of orientations, the directional-specific terminology serves for illustrative purposes only and is not limiting in any way. It is further clear to the skilled person that other embodiments may be used and structural or logical variations may be implemented without departing from the scope of protection of the invention. The following detailed description should therefore not be construed in a limiting sense, and the scope of protection of the embodiments is defined by the appended claims. The drawings, unless otherwise indicated, are not to scale.

Other features, advantages and possibilities of application of the invention result from the following description of embodiments in conjunction with the drawings.

They show,

Figure 1,

a schematic and greatly simplified representation of a reformer furnace 100 with state-of-the-art steel construction,

Figure 2,

a schematic and greatly simplified representation of a reforming furnace 200 with steel construction according to the invention,

Figure 3a

a schematic representation of the heat flow profile of a row of reformer tubes 300a according to the state of the art in bay formation and

Figure 3b

a schematic representation of the heat flow profile of a row of reformer tubes 300b according to the reformer furnace according to the invention without bays.

Figure 1 shows a simplified, schematic perspective view of a reformer furnace 100 with a steel construction according to the prior art. Essentially, the radiation space of the reformer furnace 100 is shown, which features the actual steel construction, a refractory lining, and several rows of reformer tubes and burner rows. The steel construction serves to secure the burners, reformer tubes, and supply and discharge lines to/from the burners/reformer tubes. For reasons of clarity, no details regarding the securing means are shown.

The reformer furnace 100 shown has four rows of burners 101a, 101b, and three rows of reformer tubes 102. Each of the burner rows 101a, 101b has six burners 103 arranged in a row. Each of the reformer tube rows 102 has eight reformer tubes 104 arranged in a row. The burner rows arranged respectively at the left and right edges of the figure are the wall-mounted burner rows 101a, which heat only one row of reformer tubes 102 arranged adjacent and parallel. The burner rows arranged between the wall-mounted burner rows 101a are the non-wall-mounted burner rows 101b, which each heat two parallel rows of reformer tubes 102. The reformer tube rows 102 and the burner rows 101a, 101b each extend in the z-direction of the drawing. The burners 103 each generate downwardly directed flames, i.e., the flame extends substantially in the y-direction of the drawing and thus heats the vertically arranged reformer tubes 104, which likewise extend in the y-direction. The burners 103 project into the heating space of the radiation space of the reformer furnace, which is defined outwardly as a boundary by the refractory lining 105. In this case, the vertically extending reformer tubes 103 penetrate the top and bottom of the refractory lining 105, such that the main length of a reformer tube 104 can be heated by the adjacently arranged burners. For reasons of clarity, the supply lines for supplying the burners with flue gas and oxidizer, as well as the reformer tubes with feed gas, are not shown. The same applies to the exhaust gas channels and discharge lines for extracting exhaust gases from the burner, as well as the discharge lines for removing product gases.

The steel construction of the reformer furnace shown has a total of three main support units. Each of the main support units has two vertical supports 106a and 106b, as well as a horizontal main support 107. The supports 106a, 106b each have a plinth 111. The horizontally extending main support 107 connects both vertically extending supports through a force-bearing or material-bearing connection, for example by a bolted connection or a welded connection. Of the total of three main support units, two are arranged on the front sides (front and rear sides, respectively defined by an xy plane) of the reformer furnace, and one of the main support units is arranged between these main support units arranged on the front side. In this case, the vertical supports 106a, 106b of the main support units are each arranged on the wall, whereby the main support unit arranged between the main support units arranged on the front side comprises supports 106a, 106b, which run along the lateral area (defined by yz planes) of the reformer furnace. The supports 106a, 106b of the main support units arranged on the front side run in the area of the boundary between the walls of the front sides (xy plane) and the walls of the lateral areas (yz plane) of the reformer furnace 100. The walls of the reformer furnace enclose the radiation space together with the steel construction, the refractory lining 105, and the burners 103 and the reformer tubes 104. For reasons of clarity, the walls are not shown.

Between the supports 106a, 106b of the main support units, additional auxiliary supports 108 are arranged, connected to the main supports, and extend vertically. The auxiliary supports 108 serve to further stabilize the steel structure. The auxiliary supports 108 penetrate the refractory lining shell 105 and are thus arranged partially within the heating chamber of the reformer furnace 100. In the example of the reformer furnace 100, three auxiliary supports 108 are provided for each main support unit.

In this case, the number of auxiliary supports 108 primarily depends on the width of the reformer furnace, i.e., the number of reformer tube rows and burner rows. For additional static stabilization, above the main support 107, the steel structure has a frame structure 109, which is force-coupled to the main support 107 and which has diagonally and vertically arranged struts connected to each other.

The horizontally extending main supports 107 of the main support units are arranged orthogonally to the burner rows 101a, 101b and the reformer tube rows 102. In other words, the main supports 107 extend in the x-direction of the representation, while the burner rows 101a, 101b and the reformer rows 102 extend in the z-direction of the representation. Due to the length of the reformer tube rows 102 (respectively with eight reformer tubes 104) and burner rows 101a, 101b (respectively with six burners 103), two main supports arranged on the front side are not sufficient due to static requirements. That is, the third main support unit arranged between the main support units arranged on the front side is necessary to meet the static requirements of reformer tube row length and burner row length shown. The number of main support units of a conventional reformer furnace increases in principle with the length of a row of reformer tubes 102 and the length of a row of burners 101a, 101b.

The third main support unit occupies a certain amount of space, for example due to the vertically extending auxiliary supports, which is why the distance between the third and fourth burners of a burner row 101a, 101b must be increased compared to all other burner distances. The same applies to the distance between the fourth and fifth reformer tubes of a reformer tube row 102. This design restriction results in the reformer tubes 104 in the region of the main support unit having higher operating temperatures, which generally leads to a reduced service life and/or results in higher safety requirements in the design of the reformer tubes. The higher temperatures of the fourth and fifth reformer tubes of a reformer tube row 102 in this case are caused by the fact that the visibility factor of these reformer tubes to the burner flames is higher than the visibility factor in the other tubes.

The centrally arranged main support unit divides the reformer furnace into two so-called "bays," each with three partial rows of reformer tubes, each with four reformer tubes, and four partial rows of burners, each with three burners. In principle, such a bay configuration is undesirable.

Figure 2 shows a simplified, schematic perspective view of a reformer furnace 200 with a steel construction according to the invention. Essentially, the radiation space of the reformer furnace 200 is shown, which has the actual steel construction, a refractory lining, and several rows of reformer tubes and rows of burners. The steel construction serves to secure the burners, reformer tubes, and supply and discharge lines to/from the burners/reformer tubes. For reasons of clarity, no details relating to the securing means are shown.

Analogous to the reformer furnace in Figure 1, the reformer furnace 200 shown has four rows of burners 201 a, 201 b, and three rows of reformer tubes 202. Each of the burner rows 201 a, 201 b has six burners 203 arranged in series. Each of the reformer tube rows 202 has eight reformer tubes 204 arranged in a row. The burner rows arranged respectively at the left and right edges of the figure are the wall-mounted burner rows 201 a, which heat only one row of reformer tubes 202 arranged adjacent and parallel. The burner rows arranged between the wall-mounted burner rows 201 a are the non-wall-mounted burner rows 201 b, which each heat two parallel rows of reformer tubes 202. The reformer tube rows 202 and the burner rows 201a, 201b each extend in the z-direction of the drawing. The burners 103 each generate downwardly directed flames, i.e., the flame extends substantially in the y-direction of the drawing and thus heats the vertically arranged reformer tubes 204, which likewise extend in the y-direction. The burners 203 project into the heating space of the radiation space of the reformer furnace 200, which is defined outwardly as a boundary by the refractory lining 205. In this case, the vertically extending reformer tubes 203 penetrate the top and bottom of the refractory lining 205, such that the main length of a reformer tube 204 can be heated by the adjacently arranged burners. For reasons of clarity, the supply lines for supplying the burners with flue gas and oxidizer, as well as the reformer tubes with feed gas, are not shown. The same applies to the exhaust gas channels and discharge lines for extracting exhaust gases from the burner, as well as the discharge lines for removing product gases.

The steel construction of the reformer furnace shown has a total of four main support units. Each of the main support units has two vertical supports 206a and 206b, as well as a horizontal main support 207. The supports 206a, 206b each have a plinth 211. The horizontally extending main support 207 connects both vertically extending supports via a force-bearing or material-bearing connection, for example by a bolted or welded connection. In this case, two of the main support units are arranged on the wall in the lateral areas (defined respectively by the yz plane) of the reformer furnace, and two of the main support units are arranged between the aforementioned main support units. In this case, all vertical supports 206a, 206b of the main support units are arranged on the wall. The supports 206a, 206b of both main support units arranged between the main support units arranged in the side areas run along the front side areas (defined by the xy plane) of the reformer furnace 200. The supports 206a, 206b of the main support units arranged on the wall in the side areas run in the area of the boundary between the front side walls (xy plane) and the side area walls (yz plane) of the reformer furnace 200. The walls of the reformer furnace enclose the radiation space together with the steel construction, the refractory lining 205, as well as the burners 203 and the reformer tubes 204. For reasons of clarity, the walls of the reformer furnace 200 are not shown.

Between the supports 206a, 206b of the main support units, additional auxiliary supports 208 are arranged, connected to the main supports, and extend vertically. The auxiliary supports 208 serve to further stabilize the steel construction. The auxiliary supports 208 penetrate the shell of the refractory lining 205 and are thus arranged partially within the heating space of the reformer furnace 200. In the example of the reformer furnace 200, one auxiliary support 208 is provided for each main support 207 not mounted on the wall. In this case, the number of auxiliary supports 208 basically depends on the length of the reformer furnace, i.e., on the number of reformer tubes 204 and burners 203 per row of reformer tubes or burner row. For additional static stabilization, the steel structure above the main support 207 has a frame structure 209, which is force-connected to the main support 207 and which has diagonally and vertically arranged struts connected to one another. The supports of the main support units are connected to one another by horizontally extending cross supports 210. The cross supports serve to stabilize the reformer furnace, but do not carry the main load of burners 203 and reformer tubes 204, as well as the supply and discharge lines.

According to the invention, the horizontally extending main supports 207 of the main support units are arranged parallel to the burner rows 201a, 201b and the reformer tube rows 202. In other words, the main supports 207 extend in the z-direction of the representation, which also applies to the burner rows 201a, 201b and the reformer rows 202, which likewise extend in the z-direction. By arranging the main support units according to the invention, in particular based on the main supports 207 arranged parallel to the burner and reformer tube rows, the burners 203 and the reformer tubes 204 can be arranged at a uniform spacing per row. In this case, the number of main support units required increases with the number of reformer tube rows and burner rows. In the present case, one more main support unit and one more main support unit are required per burner row than there are reformer tube rows present. In this case, the number of reformer tubes and burners is not limited upwards in principle, since as many auxiliary supports 208 as desired can be arranged between supports 206a and 207a, which extend between the reformer tube rows 202 and the burner rows 201a, 201b and thus do not interfere with the row symmetry. The steel construction according to the invention makes it possible to construct a reformer furnace that does not require "bays" due to the uniform spacing of reformer tubes. By means of the uniform spacing of reformer tubes 202 per reformer tube row, the maximum temperature per tube can be reduced, which is explained schematically by the representation of Figures 3a and 3b.

Figure 3a shows a section through a reformer tube row of the reformer furnace 100 with six reformer tubes 301a, as well as the corresponding temperature profile 302a. In this case, the main support 303a of a main support unit runs orthogonally to the reformer tube row and therefore, as explained above, requires a greater distance between those reformer tubes 301a that run in the region of the main support 303a. This results in an unfavorable temperature profile in this region compared to the remaining region of the reformer tube row. This is caused in particular by the greater visibility factor of the reformer tubes arranged in the region of the main support 303a relative to the adjacent burner flames.

Figure 3b shows the analogous case for a reformer furnace 200 according to the invention with reformer tubes 301b and the corresponding temperature profile 302b. The uniform spacing of the reformer tubes 301b also makes the temperature profile 302b uniform, thereby reducing the maximum operating temperature of a reformer tube 301b. Advantageously, the reformer furnace 200 according to the invention does not have any "bays".

List of reference signs

100 Reformer furnace (state of the art)

200 Reforming furnace (invention)

101a, 201a Burner Row (Wall Mounted)

101b, 201b Burner Row (not wall mounted)

102, 202 Row of reformer tubes

103, 203 Burner

104, 204 Reformer tube

105, 205 Refractory lining

106a, 106b, 206a, 206b Support

107, 207 Main support

108, 208 Auxiliary support

109, 209 Framed construction

210 Cross support

111,211 Zócalo

301a, 301b Reformer tube

302a, 302b Heat Profile

303a Main Support

Claims (15)

1. A reformer furnace (200) for the catalytic reforming of a carbon-containing feedstock with water vapor, having a radiation space defined by a plurality of walls, delimited from the outside environment, wherein the radiation space contains a steel construction made as a skeleton for fixing supply and discharge pipes, burners (203) and reformer tubes (204) arranged vertically, wherein the burners (203) are arranged for the generation of downwardly or upwardly oriented flames for heating the reforming tubes (204), and wherein the burners (203) and the reformer tubes (204) are arranged within the radiation space in rows as burner rows (201 a, 201 b) and reformer tube rows (202), wherein the burner rows (201a, 201b) and the reformer tube rows (202) are arranged alternately and parallel to each other, and The steel construction has a plurality of main support units, each main support unit having two supports (206a, 206b) arranged on the wall and running vertically, as well as a main support (207) connected across the supports and running horizontally, which extends over the entire length of the radiation space, and wherein the main supports (207) are configured for fixing supply and discharge pipes, burners (203) and reformer tubes (204), and The steel construction has a plurality of horizontally running transverse supports (210), which connect the supports of the main support units to each other, characterized by the main supports (207) of the main support units with respect to the rows of reformer tubes (202) and rows of burners (201a, 201b) are arranged parallel and the transverse supports (210) with respect to the rows of burner tubes (202) and rows of burners (201a, 201b) are arranged orthogonally at least in part. 2. Reformer furnace according to claim 1, characterized in that the number of main support units is a function of the number of rows of reformer tubes (202) and/or a function of the number of rows of burners (201a, 201b). 3. Reformer furnace according to claim 1 or 2, characterized in that the radiation space has a number h of main support units and has a number r of rows of reformer tubes (202), where between h and r the relation h = r 1 is taken into account. 4. Reforming furnace according to one of the preceding claims, characterized in that the radiation space has a number h of main support units and has a number b of burner rows (201 a, 201 b), where between h and b the relation h = b is taken into account. 5. Reformer furnace according to one of the preceding claims, characterized in that the number of main support units is not a function of the length of a row of reformer tubes (202) and/or the number of main support units is not a function of the length of a row of burners (201 a, 201 b). 6. Reforming furnace according to one of the preceding claims, characterized in that between two adjacent main support units - a row of burners (201 a, 201 b) is arranged or - a row of burners (201a, 201b) and a row of reformer tubes (202) are arranged adjacent to the row of burners. 7. Reforming furnace according to claim 6, characterized in that the row of individual burners is a row of burners mounted on the wall (201a). 8. Reforming furnace according to one of the preceding claims, characterized in that two of the plurality of main support units are arranged on two opposite walls of the radiation space mounted respectively on the wall, wherein the main supports of the main support units positioned on the wall run parallel to the respective wall. 9. Reforming furnace according to claim 8, characterized in that the main support units arranged on the wall have more than two supports (206a, 206b) arranged on the wall that run vertically. 10. Reformer furnace according to one of the preceding claims, characterized in that all distances between two adjacent reformer tubes (204) within a row of reformer tubes (202) and/or all distances between two adjacent burners (203) within a row of burners (201 a, 201 b) within the total radiation space of the reformer furnace are equal. 11. Reformer furnace according to one of the preceding claims, characterized in that all distances between two adjacent reformer tubes (204), measured by horizontals running measured through the adjacent reformer tubes (204) between two reformer tube axes are less than or equal to 500 mm, preferably lie in a range of 250 to 450 mm, more preferably lie in a range of 280 to 320 mm. 12. Reformer furnace according to one of the preceding claims, characterized in that the temperature of the product gas withdrawn through the discharge pipes into the medium amounts to up to 950 °C, preferably lies in a range of 900 to 950 °C, more preferably lies in a range of 925 to 950 °C. 13. Reformer furnace according to one of the preceding claims, characterized in that the steel construction serves as a skeleton for a refractory lining of the radiation space, the space within the refractory lining defining a heating space for heating the reformer tubes (204). 14. Reforming furnace according to one of the preceding claims, characterized in that each main support unit has a frame construction (209) arranged above the main support unit and connected by force to the main support. 15. Use of a reformer furnace (200) according to one of the preceding claims for steam reforming of a carbon-containing feedstock, in particular natural gas.